Chemical synthesis of polysaccharides. 7. Enzymatic hydrolysis of (1 → 6)‐α‐ DL ‐glucopyranan ( DL ‐dextran)

Abstract Hydrolysis of (1 → 6)‐α‐DL‐glucopyranan (synthetic DL‐dextran) by an endo‐dextranase from a Penicillium species was examined in an acetate buffer solution (pH 5.3) at 37°C. Three samples of different tacticities (isotactic dyad content, 55, 63, and 72%) were employed with a clinical dextran for comparison. Colorimetric determination of the reducing end units of the saccharides produced during hydrolysis showed that the maximum degrees of hydrolysis based on the D‐glucose units, (D.H.)D, for the DL‐dextrans were 21.4, 27.8, and 33.0% in the order of increasing isotacitic dyad content, whereas the (D.H.)D value for the clinical dextran was 51.9%. A statistical treatment of the enzymatic hydrolysis is proposed to interpret the experimental results.